+ //if (n % 100 == 0)
+ w.sync();
+ }
+}
+
+void rectangles(DrawingWindow &w)
+{
+ int d = 5;
+ int z = (w.width > w.height ? w.height : w.width) / 2;
+ z = d * (z / d);
+ while (z > 0) {
+ w.drawRect(z, z, w.width - 1 - z, w.height - 1 - z);
+ z -= d;